From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D4E3C3BADAA for ; Mon, 11 May 2026 13:51:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778507494; cv=none; b=YOOah47B1+3Wtyu/V4dToeyTe/W4bE0Wuqz5s0zObdp92dQJIrgIjF3stAChTkV0DJ3/yV/t4dGwDxD2hZLeOhU4kZk1VUMHL11OUgkDYmuhpLuadGQCMohjhALntZMKmkl+zA2y8puEtFwRCxVKyS8c8dz1HpF4G6GX7Gba01M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778507494; c=relaxed/simple; bh=uC5bfHxmQ5U8mVphofqZMyzonZuP8ye/EHz4NgpIM2A=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=fRRw62XUmR7ByDNS5g/ijb+ls8kP4bLBO8R8qlt+JbzRg8Sw3HnlpPjEtCHnBaoJ9t8ZtQVyePYrT+axDAknrMjS3Ej8i1jiwyXORLAombZEOfMie02mdKqNYGNZO/uq11RcOjq03rjhmoBrHrZkYnf0XJjM9VmfhlLbOkzPHL4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=umnW21h9; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="umnW21h9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A5791C2BCFA; Mon, 11 May 2026 13:51:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778507494; bh=uC5bfHxmQ5U8mVphofqZMyzonZuP8ye/EHz4NgpIM2A=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=umnW21h9/XnH7XSpLYW9KZ4S/xlKkkdzV1m8oq5Rkh0Amq/72/y/pnsKpRxabxu7V q6tfiBxdfIuq2UU5fh9f7hYOLRr9urF7vG6S5Ii7j3XkiFYEUnh5t+s+XF1jGzYgWa sIgYz+Box1fhiUSQu04Lc6Jc4LIMMPdP7B+RrH3GKdC3HQ8E0/RPRfO3q312Cz05iQ BsRwmDAwfspMG4tcSa4w/erMBbw0vLOJba6hlRGduXnomH4tarzmcwbOkR2zCzQ23f /J5qUJ858GGaB+2gB9qNj1kx5Jn4Qk7LUZKBNjldL2BOJjp85XmmNSQ14OQW2aCEvc cwe0v1ZRVj8Dw== Message-ID: Date: Mon, 11 May 2026 15:51:28 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 09/22] mm/page_alloc: don't overload migratetype in find_suitable_fallback() Content-Language: en-US To: Brendan Jackman , Borislav Petkov , Dave Hansen , Peter Zijlstra , Andrew Morton , David Hildenbrand , Wei Xu , Johannes Weiner , Zi Yan , Lorenzo Stoakes Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, x86@kernel.org, rppt@kernel.org, Sumit Garg , derkling@google.com, reijiw@google.com, Will Deacon , rientjes@google.com, "Kalyazin, Nikita" , patrick.roy@linux.dev, "Itazuri, Takahiro" , Andy Lutomirski , David Kaplan , Thomas Gleixner , Yosry Ahmed References: <20260320-page_alloc-unmapped-v2-0-28bf1bd54f41@google.com> <20260320-page_alloc-unmapped-v2-9-28bf1bd54f41@google.com> From: "Vlastimil Babka (SUSE)" In-Reply-To: <20260320-page_alloc-unmapped-v2-9-28bf1bd54f41@google.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 3/20/26 19:23, Brendan Jackman wrote: > This function currently returns a signed integer that encodes status > in-band, as negative numbers, along with a migratetype. > > This function is about to be updated to a mode where this in-band > signaling no longer makes sense. Therefore, switch to a more > explicit/verbose style that encodes the status and migratetype > separately. > > In the spirit of making things more explicit, also create an enum to > avoid using magic integer literals with special meanings. This enables > documenting the values at their definition instead of in one of the > callers. > > Signed-off-by: Brendan Jackman Reviewed-by: Vlastimil Babka (SUSE)